This invention relates to sewing machines and, more particularly, to electronically controlled sewing machines.
Sewing machines employing sophisticated electronic technology for the storage and subsequent retrieval of stitch pattern information for a multiplicity of patterns have enjoyed great commercial success in recent years. One great advantage of the use of an electronically controlled sewing machine is in its simplicity of operation and control, as perceived by the user. With the recent availability of relatively low cost microcomputers, electronically controlled sewing machines incorporating such a device have greatly increased the versatility of control afforded to the sewing machine operator. Accordingly, sewing machine designers increasingly strive to improve the versatility of the sewing machine while at the same time attempting to keep the number of operator manipulatable control elements to a minimum, so that the operator perceives the use of the machine as relatively simple in nature.
In such a sewing machine, it is common practice to provide an operator manipulatable "balance" control. The term "balance" refers to the fact that feed increments may vary from their intended values under the influence of different fabrics. Thus, patterns of stitches, wherein the sequences contain both forward and reverse feeds, may appear distorted. The severity of the distortion depends upon several factors and cannot be predetermined or preadjusted by the manufacturer. Thus, a "balance" control is typically provided on the machine to allow the operator to adjust the machine for a particular application. In practice, it is recommended that the operator sew the chosen pattern on a scrap of the particular fabric while adjusting the balance control for the most pleasing pattern appearance. Unfortunately, the term "balance control", while technically correct, is not meaningful to sewers which complicates the task in the instruction book of explaining the correct manipulation of this control. It is therefore an object of this invention to simplify both the appearance and use of an electronically controlled sewing machine with respect to the balance control function.
Since the balance control affects the feed increments and since an electronically controlled sewing machine is typically equipped with a stitch length control element, it would therefore be desirable to be able to utilize the stitch length control element for effecting the balancing function. Accordingly, it is a further object of this invention to provide an electronically controlled sewing machine without a separate balance control element and wherein the balance control function is achieved through operator manipulation of the stitch length control element.